cable reception problem

[eng3]

I'm trying to improve reception so my captures work out better.
I have in a two story house with comcast cable.
we also have cable internet

I beleive there is a seperate line running to every outlet in the house from the basement. I count 6 or 7 lines.

I have two TV's down stairs (and the cable internet box)
I notice no interference problems down stairs.

Both TV's up stairs have interference on certan channels, like a horizontal lighter line, or several vertical lines, or moving diagonal lines, or just general graininess.

I checked the basement.
here is how the cables run.
from source -> TAP
out goes to cable internet
6db tap goes to an amplifier
the amplifier is a "DROP AMP EDA 2100 +15dB"
then it goes to a 8 way splitter where it splits to the rest of the house.

They all look like RG6 cables.

I tried unplugging unused cables
I tried removing the tap (the internet latency seemed to be alot bettter, but tv reception might be worse.

Any ideas how I can fix this problem.

One TV on the second floor is directly above where the amplifer and things are so I think it may only 30ft at the most up to this room. But the cable going to the TV is rather long maybe 30-50ft
I tried replacing that cable with a shorter one that is about 10ft long. I also tried runnign that long cable down stairs to a tv that I looks fine. In both cases, it looks the same.

So I have no idea what the problem is, it doesnt sound like its the length of the cable.

[Mac Sidewinder]

This could be caused by a couple different problems. For one, an 8 way splitter reduces the signal strength more than the amplifier boosts it. And even if you unplug any unused outputs, the signal strength won't increase on the used outputs. To see if it is the splitter causing the problem, get a male to male bullet and eliminate the splitter and put the cable signal on each of the different lines one at a time. Not only will this tell you if the splitter is causing the problem, it will also test each line to see if you have a problem with a particular cable run. (You also might have a problem with a couple of your outputs from the splitter.)

If it turns out to be the splitter causing the problem, and you don't need 8 outputs, you can get a lower number of output splitter (like a 4 output), and it won't drop your signal strength as much.

Just a couple of thoughts.

Mac

[eng3]

thanks, but maybe its not a signal strength problem. or a cable problem

tv downstairs works fine
tv upstairs with my long cable is bad
tv upstairs with short cable, is bad
tv upstairs with long cable to downstairs jack, is also bad

so I don't think there is anythign wrong with the cable in the wall or my long cable.

I don't think its a signal strength problem since I see it on the downstairs tv too, but I suppose its possible that my long cable is just too long.

sometimes I see diagonal lines from left top to right bottom moving up.

here are some caps, the horizontal line does not move.
http://www.broadbandreports.com/forum/remark,8805026~mode=flat